First, the Fluval canister filter is great. I have a marineland canister, and its awesome! Second, I also have a sump on my other tank. To be honest, in my OPINION, I'd prefer my canister on a Fowlr tank. It makes 0 noise, and keeps my tank spotless! as long as you don't use bio balls or ceramic rings in your canister filter, you are ok. Even then, I kept both with live rock, and never had a problem. And I would completely disagree and I believe most people on this forum would too, that a filter sump or canister is crucial to keeping water quality livable and humane for your tankmates. Fish in the wild have the ocean, our aquariums even if they are 2000 gallons is still microscopic compared to the ocean. I couldn't imagine not having a filter!!!!!!